Hydropneumatic accumulator type power plant with differential speed motor



Sept. 2l, l94 c. L. HELBER ETAL HYDRQ-PNEUMATIC AGGUMULATOR TYPE POWER PLANT WITH DIFFERENTIAL SPEED MOTOR 3 SheetS-Sheet .l

Filed April 19, 1938 INVENTORS CRLVLE BY FRE DER/@K ATTORNEY o Sept 2l 1948- c. L. HELBER Erm. 2,449,554

HYDRO-PNEUMATIC AUCUMULTOR TYPE POWER PLANT WITH DIFFERENTIAL SPEED MOTOR 3 Sheets-Sheet 2 Filed April 19, 1958 VINVENTRS CARLYLE L. HELBER BY FREDERICK B.

\ GROSS Sept 2l 1948 c. l.. HELBER ETAL 2,449,554

HYDRO-PNEUMATIC ACCUHULATOR TYPE POWER PLANT WITH DIFFERENTIAL SPEED HOTQR Filed April 19, 1938 3 Sheets-Sheet 5 mvENToRs cARLYLE L. HELBER. BYFREDER/ck @Ross Mfr/ ATroRNEY Patented Sept. 21, 1948 HYDROPNEUMATIC ACCUMULATOR TYPE A POWER PLANT VITH DIFFERENTIAL SPEED MOTOR Carlyle L. Helber, United States Navy, and

Frederick B. Gross, Langley, Va.

Application April 19, 1938, Serial No. 202.898

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

This invention relates to a power plant, and more particularly to a hydro-pneumatic accumulator type of power plant particularly useful in connection with an aircraft launching catapult.

A further object of this invention is to provide a 4power plant which may be used in place of the power plant disclosed in the copending application of Lisle J. Maxson and Frederick B. Gross, Serial No. 189,376, filed February 8, 1938, for Flush deck catapult, and is especially intended to operate the carriage of the catapult shown in that application. In that application pneumatic pressure is utilized as the sole engine-piston actuating means. In the present invention the engine-piston is actuated by hydraulic pressure which. in turn, is actuated by pneumatic pressure.

A further object of this invention is to provide a power plant for operating an engine-piston to move'a reciprocable member with great force and at high speed Vin one direction and with little force and at slow speed in the opposite direction.

Still a further object of this invention is to provide a hydro-pneumatic power plant which may accumulate. its power from a continuously operating pump and motor and which may expend its accumulated power intermittently.

4 With the foregoing and other objects in view, v the invention consists in the construction, combination and arrangement of parts hereinafter described and illustrated in the drawings, in which Fig; 1 is a diagrammatic elevational view of the power plant of this invention Just after the commencement of the power stroke, and Fig. 2 is a fragmentary view oi Fig. 1 just after the commencement of the return stroke.

Fig. 3 is a top plan view of the power plant of this invention connected up to the engine carriage means offthe neck I8 past the opened valve piston Il from the pipe I1 of large cross-sectional area from hydraulic pressure tank portion I8. The liquid in the hydraulic pressure tank portion I8 of the iluid pressure accumulator means is kept under a desired high pressure by means of a pneumatic pressure tank portion I9 connected thereto by a pipe 28, pneumatic tank portion I9 having the air or gas therein replaceable when 2 necessary through a pipe 2| and valve 22 from any suitable source of pressure.

Liquid expended from hydraulic tank portion I8 is restored thereto through pipe 23 having a check valve 24 connected by a T-joint 28 to a continuously operable pump and motor diagrammatically shown at 28. This pump and motor 28 are connected by pipe 21 to a liquid reservoir sump 28. The T-ioint 25 is also connected by pipe 29 to the sump 28, and has an adjustable spring-loaded valve 30 therein. When used with a catapult for launching heavy aircraft, this spring-loaded valve 30 may be set at 3000 pounds per square inch. When used with extremely light aircraft it may be set as low as 1000i pounds per square inch. The pump 26 operates continuously and will pump liquid into the hydraulic pressure tank portion I'8 until the pressure therein exceeds the setting of valve 30, when this valve 30 'will open, allowing liquid to escape to the sump. Check valve 24 prevents liquid under pressure from escaping from tank portion I8. In case it is desired to launch a lighter aircraft after the valve has been set for heavier aircraft, the valve 30 will be set to the desired lower pressure and thepressure in tank portion I8 may be drained down to the desired lower pressure by means of the pressure reducing valve 3i in a pipe 32 connecting to the sump.

'I'he valve piston I6 for connecting 'pressure line I1 tothe cylinder neck I5 is itself mounted on one end of a connecting rod 33 whose other end is connected to a valve piston 34 of larger crosssectional area and movable within the enlarged cylinder 35, connected to the cylinder 38 within which the valve I8 may operate. lThis cylinder 36 is connected by a humped pipe 31 to the sump 28, the hump in 4pipe 31 being provided to insure cylinder 38 remaining constantly full of liquid. In this manner the pressure in hydraulic tank portion I8 is quickly restored after a catapult shot and maintained at a, predetermined value for the next shot. A check valve 38 is provided between hump 31 and cylinder 38 to insure that liquid may always iiow from the hump 31 to the cylinder 38, but may not tlow in anopposite direction except when the check valve is held open by means of its handle 33. This handle is connected by a link 40 to a handle 4I of a two-way valve 42 which connects a pipe 43 tothe chamber |32 within cylinder I3 between the end of the cylinder and the back face 44 of the piston I2. the pipe 43 being connected through valve 42 to a sump line 45 or to a bottle neck pressure line 46 of small cross-sectional area. The cross-section of the sump line 45 is as-great or greater than the cross-sectional area of the chamber behind the back face 44, so that liquid within the chamber I32 behind back face 44 may dow to the sump 23 without resistance. 4

A control valve 41 with a manual handle 43 is provided for controlling the operation oi the power stroke 'of the piston rod I3. This control valve 41 is provided with a pipe 43 leadingiinto the chamber 35i of cylinder 35 on the forward valve face 34| of piston valveV 34. and connects this chamber 35i to either a` sump line 53 or a pressure line 6I from pressure tank portion I3.

The valve 41 is substantially identical with the cocked control valve shown in the above-referred to application, and includes a spring 52 urging it toward the closed position shown in Fig. 2, but when open is held in such open position by means of a trigger 53 which is released when the carriage II approaches the end of its run, thus permitting the trigger 53 to be tripped and the valve 41 to return to the position connecting pressure line I to line 49 to move valve 34 and its connected valve I3 to closed position. thereby permitting the carriage Il to have its momentum absorbed by a buil'er without power being simultaneously applied thereto. t

A'threaded rod 54 and control wheel 65 extend into chamber 35 and may be threaded against forward piston face 34| of valve piston 34 to mechanically hold it in closed position when early operation of the power plant is not contemplated.

In operation, the threaded rod 64 is withdrawn to the position shown for permitting actuation of valve 34 and its connected valve I-6. It is assumed that the pump and motor 26 have been operating sufficiently to place the liquid in tank portion I3 under the desired pressure, that tank portion I3 is illled with gas or air under the same pressure, and the piston I2 and connecting rod I3 are forward adjacent the neck I5. When ready for operation the valves 42 and 33 are in the position shown in Fig. 1, being held in such position by a spring 56. The valves I6, 34 and 41 are in the position shown in Fig. 2. With the aircraft connected to the catapult carriage and ready for flight, ythe handle 43 is moved from the position shown in Fig. 2 to the position shown in Fig. l. The pressure against the forward face 34I of piston valve 34 may then escape through sump line 53, permitting the pressure from pressuretank portion I3 to now freely and rapidly through pipe I1 and to open valve I6 and pass through neck I5 into chamber I3 I against the forward face I4 o! the power piston I2, actuating power rod i3 against carriage II at high speed. The liquid during the motion of piston I2 in chamber 132 behind the rear face 44 of piston I2 escapes through sump pipe 45 to sump 23. The movement of the handle 43 from the position shown .in Fig. 2 to the position shown in Fig. 1 cocked the trigger 53. As the carriage II reaches the end of its run, it trips the trigger 53, permitting the valve 41 to be restored to the position shown in Fig. 2,

thereby connecting the high pressure line 5i to the chamber 35i against forward face 34I of piston 34. The area on the valve piston face 3M being greater than that of the face of valve piston I6, valve piston I-6 is moved to the closed position shown in Fig. 2, thus cutting ofi the pressure from tank portion I3 just at about the time that the carriage II strikes its momentum absorbing butter. As the piston I2 continues traveling under momentum liquid from hump 31 ows into chamber I3I through check valve 33, thus pre- I3. With the momentum :finally absorbed, check y valve 33 closes, preventing liquid from flowing in vthe opposite direction back to the hump, thus preventing any rebound of the power rod I3 and carriage Il. I

To restore the carriage II and power rodl I3 to initial position, the handle 4I of valve 42 is held manually retracted against spring 56 connecting pressure line 46 to the chamber |32 against the back face 44 of piston I2 and opening valve 33. This will move the power rod I0 rearwardly toward the neck I6 at relatively slow speed because of the bottleneck effect of the small line 43. The liquid against the forward face I4 meantime drains through neck I5. cylinder 36, valve 33, and hump 31 to sump 23.' When the piston `I2 has reached the forward end at the neck I3, release of the handle 4I permits valve 42 and 33 to be v automatically restored by means of spring 53 to the position shown in Fig. 1, readyfor further operation of the power plant. ,The pump and motor 26 meantime having operated continuously. the liquid in tank portion I3 is restored from sump 23 and the power plant is ready for another cycle of operation.

Other modifications and changes in the proportions and arrangements of the parts may be made by those skilled in the art without departing from the nature of the invention, within the l scope of what is hereinafter claimed.

The invention described herein may be manufactured and used by or for the Government of the United States of America. for governmental purposes without the payment of any royalties thereon or therefor. 4

What we claim is:

l. A power -plant comprising a hydro-pneumatic accumulator, a power cylinder, a piston therein having a piston rod projecting from one end of -the cylinder, said piston and rod dividing the cylinder into -a large area, high power chamber, and a small area, low .power chamber. a conduit of large cross-sectional area connecting the liquid space of the accumulator to the high power chamber to move the piston and piston rod at high speed and high power, a sump, a, pum-p for delivering liquid from the sump -to the accumulator to maintain a predetermined pressure therein. an exaust conduit connecting the high power chamber Ito lthe sump, a check valve in the exhaust conduit opening to permit iiow from the sump to the high power chamber, rst valve means selectively operable to connect the high power chamber tothe exhaust conduit or to ythe large area conduit. a passage of small cross-sectional area connecting the liquid space of the accumulator to the low power chamber, a large area passage connecting the low power chamber to the sump, second valve means selectively operable to connect the low power chamber to the small area passage or -to the large area passage, and means responsive to movement of said second valve means rto a .position connecting the low power chamber to the small area passage for opening the check valve.

2. A power plant comprising a hydro-pneumatic accumulator, a power cylinder, a piston therein having a piston rod projecting from one end of the cylinder. said piston and rod dividing the cylinder into a large area, high power chamber, and a small area, low power chamber, a conduit of large cross-sectional are-a connecting the liquid space of the accumulator to the high .power chamber -to move the piston and piston rod at high speed and high power, a sump. a pump -for deliv- 361,778 Reynolds Apr. 20.1887

-ering liquid from the sump to 'the accumulator Number to maintain 'a predetermined pressure therein. an 403,137 exhaust conduit connecting the high power cham- 410,184 ber to the sump. a hump in said exhaust con- 510,155 duit. a check valve in the exhaust conduit open- 5 551,350 ing to permit' `flow from the hump to the high 581,668 power chamber, to keep said hizh power chamber 641,132 full at al1 times. rst valve means selectively op- 663,727 erable to connect the high power chamber to the v 739,195 vexhaust conduit| or to the larle area conduit. a 10 764,522 passage of small cross-sectional area connectins 794,882 the liquid space of the accumulator to the low 353,713 power chamber. a large area passage connecting 393,365 the low power chamber 'to the sump. second valve 953,853 means selectively operable to connect the low 13 1,161,744 power chamber to the small area 'passaze or to 1,172,356 the large area passage. and means responsive to 1.519.474 movement of said second valve means to a position 1,622,029 connecting the low Vpower chamber to thesmall 1.537.369 area passage for opening the check valve. m 1,752,022 CARLYLE L. HELBm. 1,727,333 FREDERICK B. GROSS. 1,212,537

REFERENCES CITED ,4 The following references are of record in the 25 1.909.659 111e of this patent: l2,072,488 2,083,805 UNITED STATES PATENTS Number Name e Date 220.479 Johnson et ai, oct.14. i879 ao Number 234,874 Johnson Nov. so, issu 607,601

6 Name i Date Gheen May 14, 1889 Ongley Sept. 13, 1889 Von Bhler Dec. 5, 1893 Dudley Dec. 10, 1895 Smith Apr, 27, 1897 Moore Jan. 9, 1900 `Christie et al Dec. 11, 1900 Green May 17, 1904 Crowe July 5,' 1904 Pagenhart July 18, 1905 Smith Oct. 22, 1907 Holmes Sept. 8, 1908 Bulley May 24, 1910 Sparre Nov. 23, 1915 Haney Feb. 22, 1916 Hubbard Mar. 1, 1927 Dovel Mar. 22, 1927 Lapointe Oct. 9, 1928 Olsen Mar. 25, 1930 Schottler Dec. 30, 1930 Ellis June 30, 1931 Lindgren et a1 Jan. 26, 1932 Ernst et al Jan. 31, 1933 Clapp May 16, 1933 Stacy Mar. 2, 1937 Adams June 15, 1937 FOREIGN PATENTS Country Date France Mar. 29, 1926 

